• Metaplanet has purchased another 1 billion yen ($6.7 million) worth of bitcoin, pushing its holding to 639.5 BTC.

• With the purchase, Metaplanet has now bought just shy of 6 billion yen on bitcoin, purchasing them at an average price of 9.3 million yen apiece.

Japanese investment adviser Metaplanet (3350) said it bought another 1 billion yen ($6.7 million) worth of bitcoin {{BTC}}, pushing its holding to 639.5 BTC, worth approximately $40.6 million at current prices.

The Tokyo-listed company purchased around 108.8 BTC at an average price of just under 9.2 million yen per coin, the company disclosed on Monday. It has now spent just shy of 6 billion yen on the largest cryptocurrency by market value, paying an average price of 9.3 million yen apiece.

The company adopted bitcoin as a reserve asset in May as a hedge against volatility of Japan's native currency. It now has the second-largest bitcoin stash among Asia-listed companies, behind Hong Kong-based technology firm Meitu (1357), which holds around 941 BTC, according to Bitcoin Treasuries. Both companies trail behind Tysons Corner, Virginia-based MicroStrategy, which has more than 252,000 and is the largest publicly traded owner of the token.

Metaplanet recently began selling bitcoin put options, in order to use the premiums to purchase more BTC. The sale of 223 contracts on Oct. 3 earned Metaplanet a premium of 23.972 BTC ($1.44 million). A put option gives the holder the right, but not the obligation, to sell the underlying asset at a predetermined price.

Metaplanet's shares rose 7.9% to 988 yen and are over 500% higher year-to-date.

Read More: MicroStrategy's Next Bitcoin Purchase Is Likely to Take Its Holdings Above Grayscale's GBTC